Abstract: | Work schedules other than those based on the traditional 8-h workday duration have become much more common in recent years. Many such schedules compress the work week into three or four longer workdays and include an increased number of days off. In particular, rosters based on 12-h workdays have gained in popularity, and such rosters have been the focus of considerable research. The literature on 12-h workdays is, however, full of inconsistencies. Not surprisingly, there is considerable evidence from some of these studies that 12-h shifts tend to cause more fatigue than 8-h shifts. This extra fatigue may be associated with lower work efficiency, and with more errors and accidents. There is also strong evidence that workers prefer 12-h shifts due to some perceived advantages. The present paper reviews and examines these studies and their findings and discusses some possible reasons for the apparent contradictions in reported findings. Directions for decision makers and future research are suggested. |